Basic knowledge of PCBA The basic materials of PCBA are generally classified by the insulating part of the substrate. The common raw materials are bakelite, glass fiber board, and various plastic boards. PCB manufacturers generally use an insulating part composed of glass fiber, non-woven material, and resin, and then use epoxy resin and copper foil to form a "prepreg".
The common substrates and main ingredients are:
FR-1 - phenolic cotton paper, this base material is generally called bakelite (higher economical than FR-2)
FR-2 - phenolic tissue paper,
FR-3 - Cotton paper (CottON paper),
Epoxy resin FR-4 ──Woven glass,
Epoxy resin FR-5 ─ Glass cloth,
Epoxy resin FR-6 ─ Frosted glass,
Polyester G-10 ── glass cloth,
Epoxy resin CEM-1 ─ Tissue paper,
Epoxy Resin (Flame Retardant) CEM-2 ─ Tissue Paper,
Epoxy resin (non-flame retardant) CEM-3 ── glass cloth,
Epoxy resin CEM-4 ── glass cloth,
Epoxy resin CEM-5 ─ glass cloth, polyester
AIN - Aluminum Nitride
SIC - Silicon Carbide
Current status of PCBA products
pcba processing
Since the production of PCBA is in the second half of electronic equipment manufacturing, it has become the downstream industry of the electronics industry. Almost all electronic devices require the support of printed circuit boards, so printed circuit boards have the highest market share in the global electronic component products. At present, Japan, China, Taiwan, Western Europe and the United States are the main PCB manufacturing bases.
Brief description of PCBA process
SMT and DIP are both ways of integrating parts on the PCB. The main difference is that SMT does not need to drill holes on the PCB. In DIP, the PIN pins of the parts need to be inserted into the holes that have been drilled.
Circumstances in which PCBA may lead to rejection
Blow hole/pin hole, full solder paste, solder does not wet to the pad or terminal to be soldered, solder coverage does not meet the requirements, and anti-wetting phenomenon causes soldering to not meet the solder fill requirements for surface mount or through-hole insertion , the solder ball violates the minimum electrical clearance, straddles the solder connection on the conductor that should not be connected, the solder bridges the adjacent non-commonly connected conductor or the original, the solder is disturbed and violent, and the correct components are not selected according to the regulations. Not installed in the correct hole, etc.
